Step-by-step explanation
We are given the following equation and we must state the reason behind each of the steps taken to solve it:
In the first step after giving the equation 21 is being substracted from both sides of the equation. Remember that the substraction property of the equality states that any value substracted from one side of the equal sign must also be substracted from the other side. Therefore the reason behind this step is the substraction property.
Then the substractions on each side are performed. In the left side we get 21-21=0 so the constant term dissapears and on the right we obtain 21-15=6. This means that during this step only a simplification was performed.
In the following step a number 2 is multiplied to each side of the equal sign. Remember that the multiplication property of equality states that whatever is multiplied in one side of the equal sign must also be multiplied in the other side. Then the reason behind this step is the multiplication property of equality.
In the final step in the left side the 2 multiplying is simplified with the number 2 dividing and in the right side the product between -6 and 2 is performed. Then this step is also a simplification.
Answers
Then the reasons in order are:
- Substraction Property of Equality
- Simplifying
- Multiplication Property of Equality
- Simplifying